Electrical connecter



Feb. 15, 1938. H K, FOSTER 2,108,708

ELECTRICAL GONNECTER Filed March 20, 1954 INVENTOR.

Herbal"? K.FDSTE1" I jg 414% W ATTORNEYS.

Patented Feb. 15, 1938' UNITED STATES.

PATENT oi-r ce Claims.

This invention relates to improvements in electric connecters such asbase plugs, electric appliance plugs, electric attachment sockets andthe like.

5 The primary object of the invention is the provision of an improvedelectric wire connecter having improved means to facilitate and rendersecure the attachment of electric wires to the terminals or contactprongs of sockets or plug.

:-A further object of the invention is the provi sion of an improvedelectric wire connecter, such as a base plug, appliance plug or socket,having improved means for attachment of terminal wires to the contactterminals or prongs without 5 screws, removable parts or tools of anysort.

A further object of the invention is the provision of an improvedelectric wire connecter in the form of an electric appliance plug havingimproved means for attachment of another plug 80 thereto. 1

A further object of this invention is the provision of improved simpleswitch mechanism for electric appliance plugs and the like.

Other objects and advantages of the invention 26 will be apparent duringthe course of the following detailed description.

In the accompanying drawing, forming a part of this specification, andwherein similar reference characters designate corresponding parts 30throughout the several views,

v Figure 1 is a perspective view of an electric appliance plug havingthe improved features of the presentinvention embodied therein. 7

Figure 2 is a plan view of the cap end of the 35 body of the plug,showing the recessing thereof for the reception of parts of the terminalcontacts, and showing a switch arm associated therewith.

Figure 3 is a view similar to Figure 2, but with 40 the contactterminals and wires associated therewith, in place.

Figures 4 and 5 are cross sectional views taken substantially on theirrespective lines in Figure 1 or the drawing, and respectively showingswitch 45 mechanism and terminal contacts; the cap of the plug (beingshown partially removed in Figure 5. Figure 6 shows the parts arrangedas in Figure 5, but with the cap screwed tight upon the terminals.

50 Figures 7 and 8 are cross sectional views taken substantially .ontheir respective lines in Figure 6 oi the drawing. I

Figure 9 is an enlarged cross sectional view taken substantially on theline 9--9 of Figure 3, u but additionally showing the cap of the plug in(CI. lie-s32) place binding the wire to its terminal and in the cavityof the body of the plug provided therefor.

Figure 10 is a perspective view of one form of terminal contact.

Figure 11 is a perspective view of another form 5 of terminal contact.

- Figure 12 is a cross sectional view taken through a portion of a plugshowing how the terminal contact of Figure 11 is associated therewithfor clamping a wire in place. 10

Figure 13 is a perspective view of another form of terminal contact.

In the drawing, wherein for the purpose of illustration are shownpreferred and modified forms of the invention, the letter A may general-15 1y designate the improved electric wire connecter, which in thespecific embodiment shown is an electric appliance plug, such as usedfor heaters,

' toasters, and the like, but which may be an elec tric wire connecterof any type, such as an attachment plug, base plug, socket for electriclights, or the like; the essential invention residing in the improvedterminal contacts and their association with the wires to be attachedtherewith; the improved switch mechanism, and the association of adetachable plug with the' improved connecter in an improved manner.

.The appliance plug A may generally include a body B and a cap 0 havingimproved terminal contacts D and E associated therewith vfor thesecurement of electric wires thereto, as shown in Figure 3 of thedrawing. An improved switch mechanism G is provided in association withthe terminals D and E, and improved means is provided in the plug orconnecter A for detachably connecting an additional plug or electricwire connecter H thereto, as shown inFigure 7 of the drawing.

The body or casing B, as well as the cap C, are preferably made of anytype of insulation, such 40 as ordinarily used for electric plugs orconnecters, although a synthetic resin, such as Bakelite, is preferred.In the case of an electric appliance plug, such as shown, the body B isprovided with an upper cylindrical portion l5, tapering convergently atl6 and I1 towards the flattened socket inserting end I8 01' the plug.The outer periphery of the cylindrical portion I5 is screw threaded fordetachable connection of the cap'C thereon. This cap C is internallyscrew threaded at 20 and has a top wall 22 which may be provided with acentral or axial opening 23 there-.,

in for insertion of the electric cord F.

- The body 13 is provided with preferably cylinducal terminal receivingpassageways 25 and 26 therethrough, which extend from end to end of thebody. The latter in the cap connecting end is provided with elongatedrecesses 21 and 26, which are disposed in substantial parallelism, andat an end of each open into the respective terminal passageways 25 and26. This end of the plug body is also provided with transverse recesses29 and 36 intersecting the recesses 21 and 28 respectively near theirends remote from the respective terminal passageways 25 and 26. Adiametrical recess 3| is also provided in this end of the plug body,into which the recesses 29 and '36 open. This recess 3| is of course toreceive the end of the cable F and probably portions of the wiresthereof which lie at the inner side of the cap C when the latter isattached upon the body of the plug.

While in the particular electric appliance plug shown, the terminals Dand E are differently constructed, some plugs, such as base plugs, maybe provided with identical terminals or contact prongs. All of them,even including the terminals D and E, are similarly formed at theirupper ends for the clamping or connection of electric wires thereto.Thus each of the terminal devices D and E at the ends thereof areprovided with right angled extensions which are adapted to fit into therecesses 21 and 28 and to which the wires are attached. Theseextensions, as shown in Figure 10, preferably consist of upper and lowerclamping extensions or fingers 46 and 4|, which are somewhat resilientso that the electric wires may be clamped therebetween.

' They may be differently formed in departure of this general idea, forvarious purposes. Thus,

the bifurcated extension consisting of the upperand lower fingers 4 6and 4 at the extreme end of the slit 42 therebetween has an enlargedopening 43 extending from side to side, which is wider than the slit 42in order that the clamping fingers may act with greater resiliency inclamping upon the wire. The fingers 46 and are flared convergently at 44from their free ends to a point ntermediate their ends, and at thisintermediate point the said clamping fingers or extenaions are recessedat their slit faces to provide an enlarged passageway 46 for receptionof the wire therein. If desired the under-face of the lower finger orextension 4| may be similarly recessed at 46, immediately below the wirepassageway 46, since the wire is intended to be wrapped completelyaround the lower clamping finger 4|.

The terminal D in addition to the clamping finger extensions abovedescribed includes the cylindrical body 56 removably slidable into thepassageway 25 of the plug body B from the upper end thereof. Thiscylindrical body 56 is socketed at the inserting end of the plug body,and split at (see Figure 7) to receive therein the prongs of theappliance to which it may be connected, such as a heater, toaster, orthe like.

The terminal E is of somewhat different construction, since in theappliance A it is intended to provide the special switch G. Thereforethe terminal construction E consists of the wire attaching section 66and the prong connecter section 6 shown in association within theplugbody in Figures 5, 6 and 8 of the drawing. The portion 6| is cylindricalin formation, and provided with an open ended socket portion which issplit, as shown at 63 in Figure 8 of the drawing, to receive the prongof the electric appliance to which the plug is adapted to be attached. Ashort right angled anchoring extension 64 (see Figure 8) is provided atthe upper, or rather,

inner end of the section 6| which slips from the cap attaching end ofthe plug body downwardly through an anchoring socket or passageway 65,which is radially offset in communicating relation with the terminalpassageway 26. This passageway 65 extends only a portion of the lengthalong the terminal passageway 26, terminating in a shelf or shoulder tolimit the extreme movement of the terminal section 6|, at the positionshown in Figure 8 of the drawing. The switch G also aids in holding theterminal section 6| in this position, by reason of restingagainst theextension 64. Thus the terminal section 6| is anchored securely againstlongitudinal or rotative movement.

The terminal construction E furthermore includes the section 66 abovedescribed, which includes the clamping fingers 46 and 4| abovedescribed, and the cylindrical body shank I6, shown in Figureof thedrawing, which is insertable into the terminal passageway 26, as shownin Figures 5, 6 and 8 of the drawing. In its extreme position inthe-plug body B, when the cap C is clamped firmly in position thereon,the facing ends of the sections 66 and 6| are spaced, that is, outofcontact and therefore an electrical connection must be made throughthe switch G in a manner which will be mentioned hereinafter. I

' Referring to the manner of attaching the wires to the clamping fingersof the terminals and to the cam clamping, action of the cap upon thebody of the plug, the wire end 86 is either threaded through thepassageway 46, defined by recessing the fingers 46 and 4| at the splitthereof, or by slipping the wire through the flared end of the slit 42until the wire comes to rest in the socket formed by recessing 46. Theextreme end of the wire 66 is then preferably twisted, as at 82, so thatthe wire completely encompasses transversely the lower finger 4|, asshown in Figure 9.

The top surface of the upper finger 46 is preferably tapered from itsbody attaching end and also from its free end in a convergent relationto a point 96 between its ends, which is the highest level on the topsurfacing of this finger. The peak, as it may be called, is locatedimmediately above the wire receiving passageway 46.

In position the shanks or terminal bodies are of course slipped into'theplug passageways 26 and 26,-after the wires have been threaded andtwisted upon the finger extensions 4|. The wires and finger extensionsseat in the respective recesses 21 and 26 provided therefor, and thewires of course extend transversely into the common recess 3|, as shownin Figure 3 of the drawing. The inner or lower part of the wire twistedbeneath the finger 4| lies in abutment with the bottom of the recess,against the plug, andthe twisted portion of the wire is jammed into therecess joining the wire receiving recess 3 to hold it in position. Inthis relation of parts the cap C is screwed into place, coming into acam action with the peak 66 of the upper wire clamping fingers 42, andforcing the latter in the direction of the lower wire clamping finger4|, for securely and effectively clamping the wire between theseclamping fingers. The wire in fact is clamped securely in two positions,that is, against the bottom of the plug recess between the 'flnger '4l'and the same, and also between the two fingers, as shown in Figure 9 ofthe drawing. Instead of divergently tapering the upper surface oftlie'finger 46 in counter directlons, this sloping effect may be on aradius oi an arc, since it is primarily intended to have a cam actionagainst the under-surface of the cap when the latter is screwed tightthereagainst,

bar I reciprocably slidably mounted in a trans-- verse passageway of theplug body B for rectilinear movement in a line paralleling the" flatfaces of the body B. The contact bar or switch member I00 at its endsmay beprovided with suitable extensions I0'I and I02, which may besimilarly formed if desired, and both may be of insulation materialiffound preferable. In

.the simple construction shown one end of the bar I00 is angled at INand the other handle I02 is of insulation detachably screw threaded atI03, so that by removal of the handle I02the bar I00 may be readilyslipped out by pulling upon the handle IOI. The contact bar I 00, as

before mentioned, rests against the terminal extension 64, holding thesaid terminal section 6| in place. The bar I00 bridges the space betweenthe. terminal extensions 60' and BI, as clearly shown in Figure 8 of thedrawing. In its off position the contact bar I00 does not contactthe-shank end I0 of the terminal extension 60, but in the on position anoffset, preferably resilient portion I05, struck out from the materialof the bar, engages against the extreme end of the shank I0 of theterminal section 60 to bridge the facing longitudinal edges of theterminals" D and E extend slightly thereinto, so that the terminals ofthe plug H will engage in contact with the terminals of the plug A whenthey are assembled. Preferably this is accomplished'by diagonallyrecessing'the terminal shanks 50 and 6I at H5 and II 6 respectively, sothat the contact prongs-of the plug H have an effective surface contactwith the terminals of the plug B when the same are assembled. It is tobe noted that the plugH is assembled upon the plug A m that the switchcontrols passage of current to the appliances connected to both theplugs A and'H. i' I It is to be further noted that the plug H isdiagonally disposed, .so far as its axis is concerned, in acute angledrelation with respect to the longitudinal axis of the plug A. That isfor the purpose of limiting the extent of inserting ll'slmilar to thepassageway 43 of the terminal above described. In this form of inventionI may use features above described for the termi-.

nals of the plug A, but in addition I may also use an anchoring pin I20,shown in Figures 11 and 12 of the drawing, which has a pointed shankinsertable in a passageway in the upper finger 40, and which has a headforming a peak above the top surface of the finger '40, against whichthe under-surface of the cap C engages in order to force the pointed endof the anchoring pin I20 into the wire anchored between the clampingfingers 40 and M for the obvious purposes of anchoring the wire securelyand forming a positive contact therewith.

A further andsimpler form of wire connect-- ing terminal R is shown inFigure 13, consisting of a fiat shank I30, hav'ing right angledbifurcated fingers I3I and I32 at an end thereof, the slit I34therebetween being carried downwardly into the shank I30 and terminatingin an enlarged passageway I35, to insure sufficient springiness andyielding of the fingers I3I and I32, 80

that the same will clamp against the wire whenv it is anchoredtherebetween, as shown in Figure 13.

It is to be distinctly understood that the improved features of myinvention are applicable to various types of plugs and electric lightsockets, and that the terminal shank may be fiat or of any other shape.'If desired the body and cap portions of the plug may be provided withflush outer surfaces and they may be assembled together by means otherthan relative screw threading- It is apparent from the foregoing that animproved electric wire connecter has been provided which'enables thesecure attachment of the wires to the terminal or contact portionsthereof withoutthe use of any tools, and without the use of screws. Theimproved electric wire connecter is remarkably simple insofar as thenumber of Parts are concerned, when it is considered that the sameembodies not only means for effectively and positively anchoring thewires to the terminal parts, but also includes an eflicient switch andadditional plug-in feature. Of course the switch feature may beoptional, and it is to be noted that-there is no spring provided,although simple means may be provided to produce a click when snappingthe switch off and "on, if desired.

. Various changes in the shape, size, and arrangement of parts may bemade to the forms of invention herein shown and described, withoutdeparting from the spirit of the invention or the scope of the claims.

vI claim:

1. In an electric conductor connecter, the combination of an insulatedbody provided with a pair of paralleling terminal-receiving passagewaysextending therethrough, each passageway opening into an elongated recessat a face of an end of said body, said face having a centrally disposedrecess and a pair of transverse recesses,

' one communicating between one of said elongated recesses and saidcentrally disposed'recess and the other communicating between the otherof said elongated recesses. and said centrally disposed recess; a pairof substantially L-shaped resilient terminal contacts in saidpassageways and elongated recesses, said terminal contacts having meansto secure electric conductors thereto with said conductors disposedbetween the faces of said elongated recesses and said terminal contactsand extending into said transverse recesses and said centrally disposedrecess; and means to force said faces oi said terminal contacts intocontact with conductors disposed in a resilient contact finger; meansassembling the wire and terminal in the insulation body, so that thewire contacts said finger, including a portion of said finger providedwith a wire-receiving groove; and additional means movably connectedwith the insulation body for additionally clamping said finger againstsaid wire in electrical contact therewith; said last mentioned meansconsisting of a cap having a screw threaded connection with theinsulation body and the finger having a cam peak thereon disposed withits highest point immediately above said groove, said cam peak beingengageable with the cap as the latter is screwed upon the body to movethe finger into clamping engagement with the wire without distortingsaid groove to any perceptible degree.

3. In an electrical wire connecter, the combination of an electricalappliance plug having terminals provided with appliance prong-insertingsockets therein, said plug including a fiattened end adapted to beinserted into a conventional appliance socket having. a mouth larger inlength than in width, the width of said flat-' tened end being less thanthe length of a conventional plug prong, and said flattened end havingdiagonally-disposed prong-inserting sockets extending therethrough, eachof said last named sockets having a mouth at each of its ends, said lastnamed prong-inserting sockets intersecting the terminals of the saidappliance plugs and disposed so that the prongs of an additional plug,inserted in the said mouths at one end of said last-named plug-insertingsockets, will contact with the terminals of the appliance plug and willfall short of the other'mouths of said last-named sockets, whereby,because of the greater length of said diagonally disposedprong-inserting sockets as compared with the length 01' aprong-inserting socket which might extend widthwise through saidflattened end, there will be no pro jecting prong ends to lead to ashort circuit.

4. As an article of manufacture, a substantially L-shaped contactterminal for electrical conductors, comprising a terminal shank having apair of relatively spaced apart conductor wire clamping fingers thereon,of springy material, defining a slit, each finger being provided with atransverse wire-receiving groove, said grooves facing said slit andfacing each other and one of said fingers being provided with a likewirereceiving groove substantially paralleling said transversewire-receiving grooves and facing away from said slit.

5. As an article of manufacture, an electrical terminal for connectionof wire and similar conductors, comprising an electrical terminal bodyhaving a conductor attaching portion thereon provided with a slot, apair of complementary recesses facing each other and said slot, and abore extending from an outer face of said portion into said slot and toone of said recesses; and a movable prong, having a pointed end,extending from said outer face through said bore and into said slot andsaid one of said recesses,

with its pointed end extending toward the other of said recesses intobiting contact with a conductor attached to said portion.

HERBERT K, FOSTER

